A Short Definition of

Democracy

U.S. president Abraham Lincoln (1809-1865) defined democracy as:

«Government of the people, by the people, for the people»

Democracy is by far the most challenging form of government -
both for politicians and for the people. The term democracy
comes from the Greek language and means
"rule by the (simple) people".
The so-called "democracies" in classical antiquity
(Athens and Rome) represent precursors of modern democracies.
Like modern democracy, they were created as a reaction to
a concentration and abuse of power by the rulers. Yet the theory
of modern democracy was not formulated until the Age of Enlightment
(17th/18th centuries), when philosophers
defined the essential elements of democracy:
separation of powers, basic civil rights / human rights,
religious liberty and separation of church and state.

"Government by God" (in reality this means
government by religious leaders)

Dictatorship

Government by people, that have seized power by force (often:
military dictatorship)

Today, the majority of democratic countries in the world are
republics, i.e. officials are elected. Some well-established
democratic countries in Europe, however, (the United Kingdom, Spain,
Belgium, the Netherlands, Luxemburg and the Scandinavian countries)
are constitutional monarchies, i.e. a king or queen is head
of state while the constitution guarantees nevertheless all
basic rights as in any democratic republic and sets clear limits
to duties and competences of the monarch.
Such a king can be regarded as a stabilizing factor
rather than as a danger for a democracy. Therefore the classical
definition of democracy is little helpful - at least concerning
monarchy.

Because the definition of the term democracy opposite to
monarchy and aristocracy rather creates confusion with
regard to constitutional monarchies instead of establishing
clarity, it is more appropriate to define democracy opposite
to authoritarian and totalitarian regimes:

Democracy

Form of government, where a constitution guarantees
basic personal and political rights, fair and free elections,
and independent courts of law.

Totalitarian regime

Government by a little group of leaders on the basis of an
ideology,
that claims general validity for all aspects of life and usually
attempts to replace religion. The regime does not tolerate any
deviation from its state ideology. Regime opponents are persecuted,
tortured, detained in concentration camps and members of ethnic
minorities are killed in mass executions (genocide).
Historic examples of totalitarian regimes include:
National Socialism
(Germany under Hitler, 1933-1945) and Stalinism.

Authoritarian regime

Government by a little group of leaders. In contrast to
totalitarian regimes, authoritarian regimes have no distinct
state ideology and grant some amount of freedom (e.g. economic and
cultural) as long as their rule is not jeopardized.
The most important goal of authoritarian regimes is the maintenance
of power and the personal enrichment on cost of the country and
its population.

Theocracy

"Government by God": in reality this means
government by religious leaders. Usually a certain interpretation
of ancient religious laws replaces modern forms of law and is
enforced with utmost severity.
Example: Islamic Republic of Iran.

In order to deserve the label modern democracy, a country
needs to fulfill some basic requirements - and they need not only
be written down in it's constitution but must be kept up in
everyday life by politicians and authorities:

Guarantee of basic Human Rights to every individual person
vis-Ó-vis the state and its authorities as well as vis-Ó-vis any
social groups (especially religious institutions) and vis-Ó-vis
other persons.

Separation of Powers between the institutions of the state:Government [Executive Power],Parliament [Legislative Power] und Courts of Law [Judicative Power]

«No one pretends that democracy is perfect or all-wise.
Indeed, it has been said that democracy is the worst form of government
except all those other forms that have been tried from time to time»

This famous quote attributed to the former British prime minister
Sir Winston Churchill (1874-1965) focuses right on the
weak spot of democracy:
There is no such thing as the "perfect form of government"
on earth, but any other form of government produces
even less desirable results than democracy. Until today, no other
form of government has been invented that could regulate
public affairs better than democracy.